Fire Protection Flashcards
What are overhead detection sensors
Continuous loop
Continuous loop systems
Semi conductor & pneumatic presssure
What are pneumatic pressure loops manufacturers called
Systron & donner
How does pneumatic pressure work
Pressure of gas increases as temperature increases and operates switch
Semi condcutor loop names
Kiddie , graviner , Edison , Fenwal
How does semi conductor work
Tube that contains semi conductor material which decreases electrical resistance as temperature increases, alarm triggered when resistance decreases below a certain point
What’s a local fire warning
Red warning light on the overhead panel
What are central warnings
Red master warning lights , aural warning and message on ECAM/EICAS
How is central warning canceled
Pressing master warning light
What is normal condition
Open contact High resistance
What is alarm condition
Closed contact low resistance
What systems are dual loop systems
Essential fire warning systems
How does dual system work
You need to 2 detections to ensure a fire is happening , single failure doesn’t present a fire warning
When do we do a fire test
Before we start apu or engine
What does the ceramic function as in a semiconductor loop
As an endless number of resistors
What’s the tempreture coefficient of the ceramic
Negative
What loop does semi conductor use
Closed loop
When can fire not be detected in a semi conductor loop
In an open loop
What does a short circuit trigger
Fire warning
When does a short circuit happen
Resistance decreases below the alarm threshold of 500 ohms
In a dual loop system what condition is needed to trigger fire warning
Alarm condition in both loops
Max bending
3.2mm
Minimum bend radius
25.4mm
What does the first pressure switch do
Monitor or integrity switch
What does second switch do in pressure loop
Alarm switch closes at higher gas pressure caused by overheat and fire
What temperatures is high gas pressure close alarm switch
Complete loop temperature 200 degrees c
Small spot is heated to over 400 degrees c
What fire bottle is used
Halon 1301 pressurised by nitrogen at 600psi
Why is the discharge cartridge handled with care
Class c explosive
What is the wire called that causes power to burn
Squib
who can handle discharge cartridge
People who are permitted to carry class C explosives
What prevents sparks from static electricity
Electrostatic protective cap
What is discharge cartridge maximum service life
6 years
What is the date on discharge cartridge
Date of manufacture
What is the discharge cartridge shelf life
10 years
What is the purpose of the pressure switch
Controls light on the fire control panel when pressure decreases below 50% of normal pressure
How are pressure switch and indication checked
Small push button on pressure switch , aka spring loaded finger
Another method checking pressure switch and indication
Use of Allen key
What’s the Overpressure relief function
Prevent an explosion
When does frangible disc break
Pressure increases to 1700psi
What happens when bottle is discharged via thermal fuse
Amber light in cockpit and red disc is missing on the fuselage
When is yellow disc pushed out
Bottle discharges via spray nozzles
What does it mean if yellow disc is missing
Bottle is discharged and maintenance is necessary
What must you do before extinguishing a fire
Affected compartment must first isolate all supplies
How many fire extinguishing shots available per engine
2
What system does apu use
One shot system
Where is apu bottle located
Stabiliser compartment
Is apu fire extinguishing possible on ground
Yes
How does apu automatic fire extinguishing work
When fire warning activates and apu is auto shut down , circuit fires after 3 seconds
